Crack front propagation by kink formationF. Rösch and H.-R. Trebin
Institut für Theoretische und Angewandte Physik, Universität Stuttgart Pfaffenwaldring 57, 70550 Stuttgart, Germany, EU
received 21 July 2009; accepted in final form 14 September 2009; published September 2009
published online 12 October 2009
The fracture of a three-dimensional brittle solid generates two-dimensional surfaces, which are formed behind a one-dimensional crack front. For quasi-static cracks on a (111) cleavage plane in silicon front propagation by kink-pair formation was proposed and proven by a reaction pathway analysis with Stillinger-Weber potentials. Here, we demonstrate that the kink-pair mechanism is much more general: we also observe it in molecular-dynamics simulations of a complex metallic alloy, the C15 NbCr2 Friauf-Laves phase, where we applied carefully selected embedded-atom-method potentials. The numerical experiments highlight that kink formation is essential for crack propagation in any brittle material.
62.20.mj - Brittleness.
61.72.-y - Defects and impurities in crystals; microstructure.
02.70.Ns - Molecular dynamics and particle methods.
© EPLA 2009